I can't really help you, but I feel your pain :) My daughter turns 4 MAy 24th and wants a My Little Pony cake. I found a website with great ideas from real Moms, here's the link to the dinos but you can search it yourself for other things if you want:
http://www.coolest-birthday-cakes.com/dinosaur-cake.html
After looking at all of the pony cakes and realizing that I am SO not crafty enough to make anything like that, I ordered a MLP picture on Ebay that melts into the frosting. I will make her a regular rectangular cake and lay the picture on top, and viola, a pony cake. I just couldn't see myself spending 6 hours on a cake to be eaten right away the day after we get home from a 3 week vacation, which is when her party is. Good luck, anyway. Hope his cake is awesome. I remember watching the Land Before Time when I was a kid :)